Nu-substituted aminopropylamine monosulfonates



Un Ste Patent.

No Drawing. Filed Aug. 12, 1954, Ser. No. 449,496 4 Claims. (Cl. 260501)This invention relates to new chemical compounds.

j More particularly, the invention is concerned with the stabilizationof mineral oils by incorporation therein of new salt compositions.

Various mineral oils tend to deposit oil-insoluble deteriorationproducts that are formed during storage or service conditions. Forexample, straight run distillate fuel oils can form sludge duringstorage despite their high content of normally stable paraflinichydrocarbons. Where sludge deposition occurs in such oils, it is usuallyattributed to the presence in the oils of materials that are notnormally present, e.g., impurities picked up during refining, or perhapsremaining in the oil due to incomplete refining, rather than to theinherent instability of the oil itself. Sludge formation in straight runfuel oils is considered to be chiefly a problem of oxidation and theformation of insoluble oxygenated products.

Unlike straight run distillate fuel oils, catalytically cracked fuel oildistillates are rich in olefinic, aromatic and mixed olefinic-aromaticcomponents. Sludging in the latter oils is considered to involveprimarily condensation and/ or polymerization type reactions whichresult in the formation of insoluble reaction products of relativelyhigh molecular weight.

Distillate fuel oil compositions containing mixed straight run andcatalytically cracked fuel oil distillates have proved especiallytroublesome with regard to sludge deposition during storage at normalatmospheric temperatures. It has been found that the sludgingcharacteristics of such mixed, or blended, fuel oil distillates arestrikingly poor, much poorer than can be accounted for from the knownsludging characteristics of the individual component fuel oildistillates alone. While the sludge formed in mixed distillate fuel oilsno doubt contains some sludge of the type formed in each component oil,the sludge formed in the blended fuel oils is consistently greatly inexcess of the amount that can be accounted for from the known sludgingtendencies of the individual component oils, thus indicating theexistence of a special problem.

Lubricating oils, on the other hand, such as those used for crankcaselubricants in internal combustion engines of the gasoline or dieseltype, present still another problem, that is, such oils tend underservice conditions to deposit oil oxidation products, fuel soots, resinsand other oil-insoluble deterioration products on the metal surfaceswith which the oil comes in contact.

- amounts of the novel salt compositions ofthis invention.

2,989,564 Patented June 20, 1961 The salts included by this inventionare the monosulfonates of oil-soluble hydrocarbon sulfonic acids and1,3-diaminopropanes having the general formula:

R HI I'CH5CHr-CH NH where R is an aliphatic radical containing from 8 to30 carbon atoms.

The salts of this invention are prepared by partial neutralization, withan oil-soluble sulfonic acid, of a 1,3-diaminopropane that contains along-chain aliphatic radicalsubstituted, secondary amino grouping. Theaforesaid partial neutralization reaction normally takes placespontaneously at room temperature with evolution of heat, but in somecases moderate heating may be desirable in order to accelerate thereaction. In no case should the reaction be carried out at temperaturesin excess of about F., since decomposition of the resulting ammoniumsalt may occur with prolonged exposure to temperatures substantially inexcess of this limit. In order to produce the desired monosulfonatesalts, the mol ratio 'of the reactants in the neutralization procedureshould be formula: 30

where R is an aliphatic radical containing from 8 to 30 carbon atoms.

Thus, the present invention includes, for example, the use ofmonosulfonates of long-chain alkyl-, alkenylandalkadienylaminopropylamines. Specific examples of such diamino compoundsare 3-octylaminopropylamine, 3-decylaminopropylamine,3-tetradecylaminopropylamine, 3-tetradecenylaminopropylamine, 3-eicosylaminopropylamine, 3-eicosenylarninopropylarnine,3-docosylaminopropylamine, 3-docosenylaminopropylamine,3-docosodienylaminopropylamine, and 3-triacontanylaminopropylamine.Within the general class of 1,3-

diaminopropanes capable of forming the monosulfonates 'of thisinvention, the diamines in which the long-chain, aliphatic N-substituentof the secondary amino grouping is an alkyl or alkenyl group containingat least 12, and preferably from 12 to 18, carbon atoms are consideredto form especially effective addition agents. Examples of1,3-diaminopropanes which are considered to form exceptionally efiectivemonosulfonates for the purposes of this invention are the 3-dodecyl-,the 3-hexadecylaminopropylamines, and especially the 18 carbon alkyl-,alkenyl-, and alkadienyl-substituted 1,3-diaminopropanes,

such as the 3-octadecyl-, 3-octadecenyl-, and3-octadecadienylaminopropylamines. Although aliphatic hydrocarbonN-substituted 1,3-diaminopropanes are preferred, the

invention also includes salts derived from diamines in which theN-substituent of the secondary amino grouping is itself substituted withone or more groups that contain elements such as oxygen, sulfur,nitrogen or halogen and that do not interfere with the oil-solubility ofthe salt. Representative examples of 1,3-diaminopropanes containing suchsubstituents are 3-ricinoleylaminopropylamine and3-(chlorostearyl)-aminopropylamine. Mix- 3 tures of 1,3-diaminopropanessuch as are formed when the long-chain, aliphatic N-substituent in thesecondary amino grouping is derived from mixed fatty acids obtained fromnaturally occurring fats and oils form highly effective monosulfonatesalts within the scope of this invention. In such instances thealiphatic N-substituent in the secondary amino grouping will be astraight chain, mnovalent hydrocarbon radical containing from 8 to 20carbon atoms. Examples of such mixtures of 1,3-diaminopropanes are3-"tallow-aminopropylamine, 3- soya-aminopropylamine, and3-cocoaminopropylamine, Where the respective N-substituents are mixedalkyl and unsaturated alkyl groups derived from animal tallow (C -Cfatty acids, soybean (C -C fatty acids, and coconut (C -C fatty acids.

The sulfonic acids that form the monosulfonates included by thisinvention are'the'oil-soluble hydrocarbon sulfonic acids. Such acids maybe represented by the generic formula R SO H, where R is an organicradical of at least predominantly hydrocarbon character which -iscapable of imparting oil-solubility to the acid. These sulfonic acidsmay be oil-soluble aliphatic hydrocarbon sulfonic acids, includingnaphthenic hydrocarbon sulfonic acids, representative examples of theformer of which are octyl, nonyl, decyl, undecyl, lauryl, tridecyl andmyristyl sulfonic acids, and of the latter, the octyl-, dodecyl-, anddodecenyl-cyclopentyl and similarly substituted cyclohexyl sulfonicacids. Also satisfactory are the alkaryl sulfonic acids such as octyl,decyl, dodecyl and cetyl benzenesulfonic acids, as well as the so-calledkeryl, or kerosene, and wax-alkyl benzenesulfonic acids, including thecorresponding dialkyl benzenesulfonic acids. The preferentiallyoil-soluble petroleum sulfonic acids, normally referred to as mahoganyacids in order to differentiate them from the preferentially aqueousalcohol, distallation to remove the extraction solvent, and regenerationof the sulfonic acid by treatment of the residue with an equivalentamount of a mineral acid. Particularly suitable mahogany acids are thosehaving an average molecular weight between about 400 and about 650.

The reaction products of the abovedescribed partial neutralization ofthe long-chain aliphatic N-substituted 1,3-diaminopropanes withsubstantially equimolar proportions of oil-soluble hydrocarbon sulfonicacids are simple addition salts having the following probable genericformula:

wherein R and R are as defined above. Although some product may beformed in which the sulfonic acid adds to the primary amino group, theabove-indicated product tends to predominate in view of the greaterbasicity of the secondary amino group.

The preparation of the monosulfonates included by this invention,previously described in general, and a specific embodiment of theinvention are illustrated by the following specific example:

Example Oil-soluble petroleum sulfonic acids having an average molecularweight of about 430 were prepared by two successive treatments of acommercially obtained mineral a 4 oil solution containing about 30percent of the calcium salt of mahogany acids with 37 to 38 percenthydrochloric acid at 170 to 180 F., and extraction of the acidifiedproduct With benzene. The extract was then blown with nitrogen to dry.The calcium petroleum sulfonate employed had a molecular weight of 905(calculated from the base number of the 30 percent mineral oilconcentrate). Typical samples of said concentrate had the followingproperties:

Approximately 430 grams (one combining mol) of the oil-soluble petroleumsulfonic acid obtained as described above were dissolved inapproximately 1000 grams of oil and 600 grams of benzene, and theresulting solution was added with stirring to 400 grams (one combiningmo of mixed S-fatty alkyland alkenylaminopropylamines containingapproximately percent active ingredient. The latter, designated as3-tallowaminopropylamine, had a theoretical molecular weight of 320, acombining weight of approximately 400, and a melting range ofapproximately 44 to 48 C. The fatty alkyl andalkenyl substituents of thediamine were derived from animal tallow fatty acids. Accordingly, the3-talloW-aminopropylamine contained predominantly3-oleylaminopropylamine, or 3-octadecenylaminopropylamine, together withlesser proportions of 3-hexadecyland 3-octadecylaminopropylamines, andsmall amounts of 3-myristyland 3-linoleylaminopropylamines.

The crudeproduct of the foregoing reaction was a mixture ofmonosulfonates of mahogany acids and 3C alkylandalkenylaminopropylamines, the predominant component of which mixture wasthe monosulfonate of Gravity, API 26.0 Viscosity, SUV, F. 3682 Sulfur,percent 1.71 Nitrogen, percent 1.31 Acid number 34.8

The product obtained by reacting the undiluted sulfonic acids (obtainedby extraction of a 45 weight percent oil concentrate thereof with about5 volumes of a solvent comprising equal volumes of water and isopropylalcohol) in the above-indicated mol ratio with 3-tallow-aminopropylaminewas a soft tan grease at room temperature.

The foregoing example indicates the manner and ease of preparation ofthemonosulfonate salts of this invention and illustrates a specificembodiment of the invention. Specific examples of other salts includedby this invention can be prepared by reaction of substantially equimolarproportions of other herein disclosed 1,3-diaminopropanes with theforegoing oil-soluble petroleum sulfonic acids, or with other members ofthe herein disclosed class of oil-soluble hydrocarbon sulfonic acids, inthe aboveindicated molecular ratio.

The addition of minor amounts of the salts of this invention to mineraloils tending to deposit insoluble deterioration products has been foundto diminish the deposition of such materials from the oils. For example,the addition of very small amounts of monosulfonate salts of theforegoing type to distillate fuel oils, such as blended distillate fueloils cotnaining both straight run and catalyticallycrackedcomponents,.has been found to produce a markedimprovementin thesludgingtendenciesof the oils. Other distillate fuel oils are alsoimproved by the salts of this invention. In addition, lubricating'oilscontaining minor amounts of the salts of this invention exsuchmonosulfonate will depend to someextent upon the particular compoundused. Also, the minimum effective inhibitor concentration can varyconsiderably according to the specific nature of the oil to beinhibited. In general,

however, the herein disclosed salts are useful in concentrations of aslittle as about 0.005 percent to about 25 percent by weight of thecomposition. Thus, major improvement of the sludging characteristics ofdistillate fuel oils is usually obtainable by incorporation therein offrom about 0.01 to about 0.05 percent by weight of the herein disclosedclass of monosulfonates. Nevertheless, in some cases it will beadvantageous to add as much as about 0.1

.percent by weight of the inhibitor, and in unusual instances it may befound desirable to add as much as about 1.0 percent by weight of theinhibitor. The salts of this invention are important in lubricating oilsin concentrations of from about 1 to about 25 percent by weight of thecomposition. Normally major improvement in detergency properties isobtainable by the use of between about 5 percent and about 15 percent byweight of the composition. In the instance of heavy-duty type oils,

.larger amounts, e.g., up to 25 percent by weight of the compositiomcanbe used.

The monosulfonate inhibitors included by this invention may beincorporated in the oils to be inhibited in any suitable manner. Thus,the salts may be formed in situ in the oil, they may be added, per se,directly to the oil, or they may be added in the form of concentrates.In the case of a blended fuel oil they can be added either immediatelyafter blending or after the mixture has been stored for a substantialperiod of time. Alternatively, the

salts of this invention may be formed in situ in, or added per se or inthe form of concentrated solutions to one component of the blend, e.g.,either the straight run or the catalytically cracked fuel oildistillate, prior to blending. Suitable concentrates containing themonosulfonate inhibitors of this invention comprise, for example,mineral oil solutions or dispersions containing from about 2 to 50 3percent, and preferably from about 30 to 50 percent, ac-

tive ingredient. In the case of mineral oil dispersions it may bedesirable to heat the dispersion and/or the oil that is to be inhibited,e.g., to a temperature of from about 100 to about 140 F., in order tofacilitate blending. An

alternate practice involves blending at ordinary atmospherictemperatures, using a solution of the inhibitor in a solvent that has alarge solubility therefor, e.g., benzene,

I isopropanol or methyl isobutyl ketone, and that does not adverselyaffect the stability of the oil.

As indicated, the salts of this invention are adapted to improve thestability of a variety of oils. The class of distillate fuel oils towhich this invention is applicable includes those containing straightrun and/ or catalytically .cracked fuel oil distillates such as are usedfor domestic heating and for some industrial heating purposes, typicalof which are the so-called No. 2 fuel oils, i.e., distillate oilsboiling within the approximate range of 350 to 750 F. and having aminimum API gravity of about 26. The

ratio of the volume of the catalytically cracked to the straight run oilis within the range of about 9:1 and about 1:9. It is especiallyadvantageous when applied to mixed oils containing these oils in avolume ratio within the range of 4:1 and 1:4.

. Xe. Lubricating oils that are benefited by the salts-of this inventioninclude those derived from Coastal, Mid- Continent and Pennsylvaniacrudes, whether acid treated -or solvent treated. The invention isespecially important in the improvement of lubricating oils that areadapted for use as crankcase lubricants.

The utility of the herein disclosed class of monosulfonate salts oflong-chain, aliphatic N-substituted 1,3-diaminopropanes has beendemonstrated by subjecting various mineral oil compositions containingthe same to standard test procedures designed to evaluate variouscharacteristics of the oils. For example, mixtures of catalyticallycracked and straight run fuel oil distillates containing variousconcentrations of representative salts of the class included by theinvention have been subjected to a standard accelerated stability test.The test samples were made up -by adding the desired concentrationofeach additive to be tested to separate samples of various fuel oilmixtures containing 50 percent by volume of a straight run No. 2 fueloil distillate and 50 percent by volume of a catalytically cracked fueloil distillate, and having varying sludging characteristics.

The stability test referred to above was carried out on the mixed fueloil compositions by heating 600 gram samples of the fuel oilcompositions for a period of 16 hours at 210 F. in loosely stoppered,one-quart clear glass bottles. Following the heating period each testsample was cooled to room temperature and filtered by suction through atared, medium porosity, fritted glass Goochtype crucible. The sludge ineach crucible was washed with heptane. Complete removal of the sludgeadhering to the inside of the bottles was obtained by means of a rubberpoliceman and heptane. The respective crucibles were dried in an ovenmaintained at 210 F. for 1 hour, cooled in a desiccator and reweighed.The increase in weight was recorded as milligrams of sludge per 600grams of oil.

The efiectiveness of the herein disclosed class of monosulfonates toimprove the sludging characteristics of distillate fuel oils isconsidered to be peculiar thereto and is demonstrated by the fact thatcorresponding disulfonate salts of the herein disclosed long-chain,aliphatic N-substituted 1,3-diaminopropanes and sulfonates of lowmolecular weight 1,3-diaminopropanes do not as a class exhibitappreciable sludge inhibition in distillate fuel oils. Similarly, noappreciable inhibition of sludge deposition in distillate fuel oils isobtained with monosulfonates of non-oil-soluble hydrocarbon sulfonicacids and long-chain, aliphatic N-substituted 1,3-diaminopropanes.

As illustrating the improvement obtainable with the class ofmonosulfonates included by this invention arid also by way ofillustrating the unique nature of the properties of these compounds, thespecific results obtained by testing fuel oil compositions containingthe following additives are set forth in tabular form elsewherehereinafter: 3-tallow-aminopropylamine mono-petroleum sulfonate(prepared in accordance with the foregoing specific example),3-tallow-aminopropylarnine di-petroleum sulfonate (prepared by reactingthe diamine and the petroleum sulfonic acid of the example in a 1:2 molratio), 3-laurylaminopropylarnine di-petroleum sul-fonate (prepared byreacting 3-laurylaminopropylamine and the petroleum sulfonic acid of theexample in a 1:2 mol ratio), 3-tallow-aminopropylamine mono-toluenesulfonate, 3- isopropylaminopropylamine monosulfonate (prepared byreacting 3-isopropylaminopropylamine and the petroleum sulfonic acid ofthe example in a 1:1 mol ratio), the corresponding disulfonate,3-diethylaminopropylamine monosulfonate (prepared by reactingdiethylaminopropylamine with the petroleum sulfonic acid of the examplein a 1:1 mol ratio), and the corresponding disulfonate.

The fuel oil mixture referred to as Blend A in the following table was a1:1 by volume mixture of Eastern Venezuela straight run and fluidcatalytically cracked No.

, tion.

2 fuel. oil distillates and had the following physical-properties:

Gravity, API 3.4.0 Viscosity, jSUS 35.2 Color, NPA 2.5 Pour point, F.Flash point, .00, F. 170 Carbon residue, Conradson 10.01 Neutralizationvalue, base No 0.05 Distillation:

Initial boiling point, F. 376

End boiling point, F 632 Bromine No. 10.4 OIefins, wt. percent 14.0Aromatics, vol. percent 21.5 Aniline point 135.7 Ash, oxide, wt. percent0.01

The foregoing properties are typical of, although not necessarilyidentical with, similarly compounded Blends B, C, and E, and morecomplex Blend D.

TABLE A Sludge, lug/600 g. Oil, After 16 Hrs.

1. Blend A50/50 (vol) Mixture of Mid-Continent SR.

and F.C.C. No. 2 Fuel Oil Distillate 35. 8 2. Blend A plus 0.02 vol.percent 3-Tallow-aminopropylamine Mono-Petroleum Sulfonate 2. 8 3. BlendA plus 0.02 vol. percent 3-Tallow-aminopropylarnine Di-PetroleumSultanate 74. 0 4. Blend A plus 0.04 vol. percent 3-Tallow-arni.no-

propylamine Di-Petroleum Sultanate 84. 6 5. Blend B50/50 (vol.) Mixtureof E.V.S.R. and F.C.G.

No. 2 Fuel Oil Distillate 14.0 6. Blend B plus 0.02 wt. percent3-Tal1ow"-aminopropylamine Mono-Petroleum Sulfonate 1. 7 7. Blend C50/50(vol.) Mixture of E.V.S.R. and F No. 2 Fuel Oil Distillate 16. 3 8.Blend 0 plus 0.02 vol. percent 3-Laurylaminopropylamine Di-PetroleumSulfonate 16. 4 9. Blend 0 plus 0.03 vol. percent3-Laurylaminopropylamine Di-Petroleum Sull'onate 23. 3 10. BlendD-Mixture of )4 W.'I.S.R./% S.L S R./%

F.0.0. N0. 2 Fuel Oil Distillate 1 7. 2 11. Blend D plus 0.02 Wt.percent 3-Tallow"-aminopropylamine Mono-Toluene Sulfonate 98. 5 12.Blend E-50/50 (vol.) Mixture of Mid-Continent S.R.

and F.C.C. No. 2 Fuel Oil Distillate 18.0 13. Blend E plus 0.02 vol.percent 3-Is0propylaminopropylamine Mnnnsnlfnnate 0- 3 14. Blend E plus0.02 vol. percent 3-Isopropylarninopropylamine Disulfonate 52. 4 15.Blend E plus 0.02 vol. percent,Diethylaminopropylamine Monosultonate43.4 16. Blend E plus 0.02 vol. percent DiethylaminopropylamineDisnlfnnatp 54, 1

1 Blend 0133.33 vol. percent each of West Texas Straight Run, SouthernLouisiana Straight Run, and Fluid Catalytically Cracked No. 2 Fuel onDistillates.

Fuel oil Compositions 2 and 6 in the foregoing table and the inhibitorsused therein are specific embodiments Y of the invention, and theresults shown in the Table for these compositions are considered typicalof thoseobtainablewith the monosulfonate salts of the class included bythe invention. Comparison of the results obtainedjfor Compositions 2and'6 with corresponding blank Compositions 1 and 5 clearly indicatesthe marked improvement in sludging characteristics of mixed distillatefuel oils that is obtainable with the salts included by this inven- Onthe other hand, comparison of the sludging characteristics ofCompositions 3 and 4 and-Compositions 8 and 9 with those for therespective blank Compositions 1 and 7 indicates that the correspondingdisulfonate salts do not as a class function similarly as themonosulfonates included by this invention. Similarly, comparison of theresults obtained for Composition 11 with those obtained with blankComposition clearly indicates that monosulfonate salts ofnon-oil-soluble hydrocarbon sulfonic acids also fail to improve thesludging characteristics of mixed catalytically cracked and straight runjfuel oils. Comparison of the, sludging characteristics for,Compositions .13 to 16, inclusive, withthose for blank Composition 12indicates that low molecular weight 1,3-diaminopropane sulfonates areunsatisfactory inhibitors.

' The addition agents of this invention are especially advantageous inthat they are essentially ashless in character.

It will be understood that the foregoing examples of the invention are.merely illustrative and that other members of the class ofsludge-inhibiting salts included by the invention can be used in thesame concentrations, or in other concentrations within the hereindisclosed ranges, to prepare mixed catalytically cracked and straightrun fuel oil compositions having similarly improved sludgingcharacteristics. Specific examples of other monosulfonate salts that aresuitable for the purposes of this invention are the mono-laurylsulfonates, mono-myristyl sulfonates, mono-dodecylcyclohexyl sulfonates,mono-naphthenyl sulfonates, mono-dodecylbenezene sulfonates,mono-cotylbenezene sulfonates, mono-kerosense-alkylbenezene sulfonatesand mono-wax-alkylbenzene sulfonates of 3-dodecylaminopropylamine,3-tetradecylaminopropylamine, 3-hexadecylaminopropylamine,3-octadecylaminopropylamine and 3-octadecenylaminopropylamine. Otherspecific examples of suitable additive agents included by the inventionare mono-sulfonates corresponding to those listed above of mixed fattyalkyl-and alkenylaminopropylamines such as 3-"ta1low-aminopropylamine,3-cocoaminopropylamine and 3-soya-aminopropylamine. The foregoingadditives can be substituted in the fuel oil composition exemplified byCompositions 2 and 6 in the same or equivalent proportions withbeneficial results. Examples of other fuel oil blends are thosecontaining catalytically cracked and straight run distillates in thevolume proportions 1:9, 1:4, 4:1, 9:1. The above-listed compounds can beadded to these blends in the proportions disclosed, for example, 0.01,0.02, 0.03, 0.04, 0.05 percent by weight, with good results.

The monosulfonates of this invention also inhibit deposition ofoil-insoluble deterioration products from other mineral oils. Forexample, a solvent refined lubricating oil derived from a Mid-Continentcrude oil and having a viscosity of about 450 S.U.S. at F. was comparedwith a sample of the same oil containing 10.0 percent by weight of3-"talloW-aminopropylamine mono-petroleum sulfonate prepared inaccordance with the procedure of the foregoing example, and with anothersample of the same oil containing 12.7 weight percent of 3-talloaminopropylamine di-petroleum sulfonate. The sulfonates tested were inthe form of oil concentrates, and the monosulfonate concentrate had thefollowing inspection:

Acid number 31.30 Sulfur, percent 1.73 Nitrogen, percent 1.28

The inspection data for the base oil and for the oil sample containingthe specific monosulfonate mentioned above are shown below:

The oil containing the above-indicatedmonoand disulfonates weresubjected to Single Cylinder Lauson (Diesel ProcedureyEngine Tests. Thetests-were carried out in the standard Lauson Model H-2 single cylinder,

9 liquid cooled, four cycle gasoline engine under the followingconditions:

Fuel Laboratory supply of L-4 test fuel.

Jacket temperature 300:2" F.

Oil temperature 22Si2 F. sump temp.

Load Full 3 H.P.

Speed 1860 r.p.m.

Oil charge 2.1 lb.

Air-fuel ratio 13.0:1.

Piston Aluminum with 3 rings.

This test consists of a series of 24 hour runs continued for a total of216 hours unless ring sticking or excessive piston deposits warrantstopping the test earlier. The oil is rated on the following basis:

(1) Piston Varnish Rating in which the piston is compared to a set ofstandard pistons and visually classified. The rating ranges from 10 fora completely clean piston to for a heavily varnished and lacqueredpiston.

(2) Number of stuck rings.

(3) Merit Rating which is a visual rating and consists of evaluatingover-all engine cleanliness and takes into consideration the followingfactors: ring sticking, oilring plugging, and piston skirt deposits. Amerit rating of 100 is perfect (no stuck or plugged rings, no pistonskirt deposits).

The results of the test oils are shown below together with the resultsobtained with a typical sample of the uninhibited base oil:

1 Test stopped because of poor piston varnish rating.

Composition 2 in the foregoing Table B is a specific embodiment of theinvention, and the results obtained therewith are considered typical ofthose obtainable with other lubricating oil compositions within thescope of the invention. Comparison of the test results for Compositions1 and 2 of the foregoing Table illustrates the improvement obtainablewith the salts of this invention. Comparison of the test results forCompositions 2 and 3 in the foregoing table shows that the advantageousproperties of the salts of this invention are peculiar to themonosulfonates.

The foregoing embodiment of the invention is illustrative; other of themonosulfonate salts of this invention can be substituted in theforegoing lubricant composition in the same or equivalent concentrationswith beneficial results. Examples of other compositions included by theinvention are lubricating oils containing from 1 to 25 percent by weightof the composition, e.g., 5, 10, 15, 20 percent, of the mono-laurylsulfonates, mono-myristyl sulfonates, mono-dodecylcvyclohexylsulfonates, mono-naphthenyl sulfonates, mono-dodecylbenzene sulfonates,monocetylbenzene sulfonates, mono-kerosene-alkylbenzene sulfonates of3-dodecylaminopropylamine, 3-tetradecylaminopropylamine,3-hexadecylaminopropylamine, 3-octadecylaminopropylamine and3-octadeceneylaminopropylamine.

It will be understood that the oil compositions of this invention maycontain, in addition to the additives disclosed herein, otherimprovement agents adapted to improve the oils in one or more respects.For example, the stable fuel oil compositions of this invention maycontain additionally oxidation inhibitons, flash point control agents,corrosion inhibitors, anti-foam agents, ignition quality improvers,combustion improvers and other additives adapted to improve the oils inone or more respects. The lubricating oil compositions of this inventionmay contain additionally, for example, anti-oxidants, detergents, pourpoint improvers, viscosity index improvers, thickencrs, corrosioninhibitors, anti-foam agents and other additives for improving theproperties of the oil.

It will be apparent to those skilled in the art that many variations ofthe invention may be resorted to without departing from the spiritthereof. Accordingly, only such limitations should be imposed as areindicated in the claims appended hereto.

We claim:

1. A monosulfonate of an oil-soluble hydrocarbon sulfonic acid and a1,3-diaminopropane having the general formula:

where R is an aliphatic radical containing from 8 to 30 carbon atoms.

2. A monosulfonate of an oil-soluble petroleum sulfonic acid and a1,3-diaminopropane selected from the group consisting of 3-alkyland3-alkenylamino-propylamines wherein the alkyl and alkenyl substituentscontain from 12 to 18 carbon atoms.

3. The monosulfonate of oil-soluble petroleum sulfonic acids and3-oleylaminopropylamine.

4. The monosulfonate of oil-soluble petroleum sulfonic acids and mixed3-alkyland 3-alkenylamino-propylamines wherein said alkyl and alkenylsubstituents contain from 14 to 18 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS2,130,947 Carothers Sept. 30, 1938 2,321,496 Liberthson June 8, 19432,533,302 Watkins Dec. 12, 1950 2,684,292 Caron et al July 20, 19542,736,658 Pfohl et a1 Feb. 28, 1956 2,771,348 Meguerian Nov. 20, 6

1. A MONOSULFONATE OF AN OIL-SOLUBLE HYDROCARBON SULFONIC ACID AND A1,3-DIAMINOPROPANE HAVING THE GENERAL FORMULA: